Distance Protection Relay for Transmission Lines

SIPROTEC 7SA522

Description

SIPROTEC 7SA522 Distance Protection

Perspective view

The SIPROTEC 7SA522 relay provides full-scheme distance protection and incorporates all functions usually required for the protection of a power line. The relay is designed to provide fast and selective fault clearance on transmission and subtransmission cables and overhead lines with or without series capacitor compensation. The power system star point can be solid or resistance grounded (earthed), resonant-earthed via Peterson coil or isolated. The SIPROTEC 7SA522 is suitable for single-pole and three-pole tripping applications with and without tele (pilot) protection schemes.

The SIPROTEC 7SA522 incorporates several protective functions usually required for transmission line protection.

High-speed tripping time

Suitable for cables and overhead lines with or without series capacitor compensation

Self-setting power swing detection for power swing frequencies up to 7 Hz

Digital relay-to-relay communication for two and three terminal topologies

Adaptive auto-reclosure (ADT)

Functions

Protection functions

Non-switched distance protection with 6 measuring systems (21/21N)

High resistance ground (earth)-fault protection for single and three-phase tripping (50N, 51N, 67N)